Evolution Under the Microscope
The striking image on the cover of this book is a crystal of DNA. What more effective illustration could one imagine for a book which deals with the significance of biochemistry for our understanding of biology?
The modern interpretation of cell biology followed, for the most part, the 1953 elucidation of the DNA double helix. David Swift, a man initially perfectly happy with the neo-Darwinian synthesis, could not help reflecting on the implications of this new information. Something was terribly wrong with evolution theory. Indeed, he eventually concluded that “the complexity of biochemistry is the reef on which the theory of evolution founders.” (p. 187).
In his main argument, the author establishes that evolution, if it is to occur, requires random mutations. However this has important implications. Firstly he examines the probability of the spontaneous appearance of even one large protein molecule, for example cytochrome C (essential in energy transfer). Next he discusses the many known variations (among diverse organisms) on the cytochrome C theme. Do these prove that the molecule could have risen gradually? Apparently not. Firstly he examines the many positions in the cytochrome C molecule where no variation is found or presumably possible.
Next he examines other important macromolecules such as ubiquitin (involved in DNA repair), histone H4 (part of chromosomes), actin (part of muscle), and rubisco (involved in photosynthesis), all of which have high numbers of amino acid positions which are invariant (no substitutions possible). The situation stems, he declares, from the requirement for precise folding and precisely located active sites. Without these, the molecule has no activity. The flexibility in choices of amino acids in exterior positions does nothing to overcome the prohibitive improbability of developing the critical interior of each molecule (p. 155).
Next he considers phylogenetic trees based on variations in “homologous” molecules. It is the author’s contention that such trees show at best how relatively inconsequential changes might have taken place. What they do not show however is how an efficient modern protein could develop from a crude early form. Indeed, the author declares, when proteins first appear, they are already in fully functioning form (p. 157).
Concerning arguments involving sequence or gene duplication as sources of new molecules, the author discusses the cases of haemoglobin and myoglobin, and ferrodoxin. He demonstrates that these molecules work only when fully three-dimensional with active sites in appropriate positions. Smaller parts of the molecules would be of no benefit and would be selected against. Moreover a protein needs to be a minimum of 70 amino acids long for folding to occur properly. This process is highly sensitive and even slight variations in sequence can result in failure. Indeed he declares that “the criterion for folding by itself, is probably enough to defeat any attempt at finding a protein randomly” (p. 176). But there is more bad news. Every gene for a protein also requires at the same time, the operation of numerous control sequences in order for the macromolecule to be expressed. And even if it were produced, the protein requires the cooperative action of numerous other proteins in order for it to be effective. These simultaneous requirements push the probabilities for random development of macromolecules basically down to never never land.
While the author agrees that the operation of natural selection is real and has important implications for ecology, he now realizes that evolution and natural selection are not the same thing (p. 220). While the effects of natural selection are to shuffle and segregate various versions of a gene, macroevolution requires new information in the form of new genes. Natural selection cannot provide that (p. 247). The popular examples of resistance to antibiotics and insecticides, he points out, upon closer examination turn out to be unfavourable mutations in already existing genes (pp. 235-244). Based on his new understanding of macromolecules, he declares that “the fundamental evolutionary principle of incremental progress fails completely at the level of molecular biology” (p. 318). That is the death knell for the neo-Darwinian synthesis.
Based on his conclusions from molecular biology, in similar vein, the author discusses origin of life speculations, the origin of the eukaryotic cells, and the origin of sex. In every case he considers molecular details which are devastating to evolution. Also he considers cladistics and homology.
No discussion of origins is complete without reference to the fossil record. Based on molecular biology and population genetics, David Swift had already concluded that primordial organisms were equipped with all the genetic information they would ever need and that these early populations rapidly diversified by gene segregation into clusters of related taxa (p. 250 and 257). This sounds very close to archetypes or the modern creationist concept of baramins (created kinds). With a view such as this, the author is obviously going to be critical of modern conclusions on the fossil record. Indeed what he sees is a record of sudden appearances in the strata: “No phylum can be traced from a preceding one in the fossil record, in fact we cannot account for the origin of a single phylum: they all appear abruptly. This is also true of lower taxonomic groups such as classes and orders, and possibly lower still” (p. 295).
This book demonstrates what happens when an individual really looks at the evidence from nature. The author prefaces his main argument (which does not begin until p. 115) with a somewhat tedious review of the history of science. Once he reaches the main body of this work however, the text comes alive. It is clear, interesting and with occasional glimpses of humour. The book includes few footnotes, but this probably makes it easier to follow. This book is ideal for university students and scientifically literate adults who seek a current introduction to the problems with evolution theory. This is a highly effective book which we will surely want to distribute on university campuses everywhere. Is there a student in your life who would benefit?
David W. Swift. 2002. Evolution Under the Microscope: a Scientific Critique of the Theory of Evolution. Leighton Academic Press, Stirling University Innovation Park, FK9 4NF, UK. 423 pages.
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